gowley



J. T'. COWLEY POWER CONTROL DEVICE Jan. 5 1926.

Filed April 8, 1925 2 Sheets-Sheet l Jan. 5 1926.

` J. T. cowLEY POWER CONTROL DEVICE Filed April a, 1925 2 Sheets-Sheet 2 I 17 rv@ n te f1: J'wW/@SYZ' 'owley. 0?/ @a 'Patented Jan. 5, 1926.

JAMES T. COW'LEY, GF

nsw Yoan.

POlER-CGNTROL DEVICE.

Applcatioxrled ApriLS, 19255-, SeraLNo. 21,719.

To @Nal/Ilma t may concern Beit known that I., .latms'll CowLnY, a.

daga and State ofi-New. York, have invented,

new and usetul-q Improvements inv Power- Control Devices, ofl which the followingis ai specification. y

rllhis.invention. pertains to power control,- lerslfor. pneumatic despatch-,systems andyrelates more. particularly to automatically act-- ing controllers thesofealledi minimum flow type of which the patent to Libby,

968,578, August 30, 191.0, furnishes an early example.

Contnollers of this type comprise essenf tially a` valve, hereinafter. referred to as the main valve, located between the transmission. tube and an ain exhauster, or vacuumdrum, such valve cutting oiff carrier propeli ling. aiutlow through the tube when the tube is idle, although thereis at all times a.continu.- ous flowvof air through thetrausmission tube of. relatively small volume, insufficient to propeb a carrier, and known as the minimum flow, anda. pneumatic, for example-a piston-i o1;v diaphragm which responds either direct-ly or indirectly to changes in pressure in the tube due to the momentary cutting offorlcheclri'ngof theminimuni flow of; air incident tothe inSertion of a carrier in the tube, and; which` by such response opens wide the malinl valve topermit a carrier propelling. air currentto flow through the transmission tube.

lu the form of apparatus described in the Libby patent the period during which the ralveren'iains open is determined solely by the operation of a timing device. The present invention is intended to improve the operation of devices of this general typev by eliminating the timing devicefand*` in place thereof providing means which is responsive directly to the change of pressure in the transmission, tube incident to discharge of the last carrier therefrom for initiating clo, sure of the maincontrolling valve.

ln the accompanying drawings a preferredembodiment 0f the invention is illustrated by way oil-example,

lliff. l bei-ng, a diagrannnatic elevation, partiti; iirsection, showing the. improved conf tioller installed. between one trausmissioni tube of. a pneumaticsystem` and the exhaust. headerthereof. I l

Fig. 2is a fragmentary-vertical section to much langer y scale showing. thevl interior con.- struction. of the controller, theparts beingA in` normal position w-ith,tlie malin valveclosed;

Fig. 3 is a. fragmenta'nysection showing. 60 certain'. ofthe parts in the. position which they occupy when themain. valve isopen` and while the carrier is in flight through. the tube.; 'i

Fig. l, is a fragmentary section showing G5 certain ofr the, parts illustnated in Fig. Si but occupying` the. position which they assume immediately upon delivery off the last carrier from the transmission tube and. before the main valve has closed;

Fig. 5 is a fragmentary elevation, to somewhat larger scale than F ig. l, showing the lower part of the controller with its casing, broken away to illustrate. the interior construction; and 75 Fig'. 6 isa plan. view oft the controller to substantially the same scale as Fig', 2.

ReferringL to Figs. l and 5.of the drawings, the numeral, l indicates a portion of a central, station desk provided with the despatch 80 terminal 2 forming. a part of the sending transmission tube 3 leading to an outlying station. The correspondingreturn transmission tube Ll is, provided with the usual normally closed deli-very terminal 5 and with S5 the extension tube 6 which passes down through. the top ofthe ydesk l and is connected with the. power control apparatus indicated generally bythe numeral 7. A suction tubo 8 leads from the power control ap- 90 paratus to the usual suction drum or header 9 in which a vacuum or low pressure is maintained by means of a suitable cxhauster not shown. A continuous air passage or conduit is thus provided extending. from the 95 terminali to the exhaust, that portion of the conduit provided by tubes 3V and tforming the transmission line.

The power control apparatus 7 which foi-'nis the immediate subject matter of the "1" present invention preferably comprises an elongate casing 10 (Figs. l and 5.) having an openingr in its side wall.` defined Aby flange 1l for the reception of the end ofv the tube enftension 6. The lower end of this casing is also furnished with an opening defined by a flange 12 for the reception of the end of the suction tube 8.

The interior of the casing 10 is divided into an inlet chamber 13, communicating at all times with the transmission tube, and an outlet chamber 14, communicating freely with the suction tube 8, by a partition or septum 15. Preferably this partition is of U-shape, comprising the substantially parallel spaced walls 17 and 18. These walls are furnished with coaxial valve orifies providing communication between the chambers 13 and 14, Normally these orifies are closed by means of the heads 19 and 2O respectively of a valve 21 of balanced type. lVhile a valve of this type is preferred, the particular form of valve employed is not essential to the present invention and it is contemplated that other types of Ivalves, for example a valve having a single head cooperating with a single Valve orifice, may be employed if desired.

As herein shown the tubes 6 and 8 are connected by means of a small pipe 6:l which permits a constant flow of air of small volume to be drawn through the transmissiony tube, such flow being known as the minimum flow. While it is preferred to employ this small pipe disposed outside of the casing 10, similar results may be secured by providingr a small passage through the septun 15, or alternatively by permitting leakage past the valve heads.

The upper wall 10a of the casing' 1() is preferably provided with a removable seetion 22 (Fig. 3) for convenience in assemblage of the parts. This removable section or cover is furnished with a central boss 23 having a guide passage for the stem 24 of the main valve 21. The upper wall 10a of thel casing is extended laterally and upwardly to provide the saucer shaped lower member 1()b of the main pneumatic motor casing. This bottom member 10b terminates in a flange 25 forming a seat for the edges of a flexible diaphragm 26 which is clamped between the flange 25 and a flange 27 forming the edge of a downwardly concave cover member 28. The cover member 28 and the bottom member 10h may be connected by bolts 28a or other suitable securing means.

The casing comprising the members l0" and 28 is divided by the diaphragm 26 into upper end lower chambers 29 and 30 respectively. The chamber 30 is always in free communication with the outer atmosphere by means of a port or ports 31. AV small bleeder opening 42, preferably controlled by a needle valve 43, allows air at atmospheric pressure slowly to leak into the chamber 29 of the main motor.

The central part of the diaphragm 26 is preferably clamped between stiffener plates 32 and 33. These plates and the diaphragm are provided with central apertures for the passage of the reduced and screw threaded upper end 34 of the stem 24 of the main valve. A nut 35 engaging the member 34 clamps the plates 32 and 33 against the diaphragm.

An internally screw 'threaded sleeve 36 engages the upper end of the stem 24 above the nut 35 and constitutes a socket for the screw threaded lower end of a rod 37 which forms an extension of the stem 24. The rod 37 slides in a guide opening in the upper end of a hollow gland 38 having screw threaded engagement with an opening in a boss 39 projecting from the upper surface of the cover 28. A coiled spring 40 surrounds the rod 37, having one of its ends bearing against the inner surface of the gland 38 and its other end bearing against a radial flange 41 on the sleeve 36. This spring tends to depress the diaphragm 26 and thus to close the main valve, and its tension may be varied by turning the gland 38.

The cover 28 is provided with a large opening surrounded by an annular flange 44. A flange 45 projecting from the base member 46 of an auxiliary motor casing is secured to the flange 44. The base member` 46 of the auxiliary motor casing is furnished with an upstanding cylindrical wall 56 terminating in a radial flange 57 which supports the outer edge of a flexible diaphragm 58. This diaphragm is clamped between the flange 57 and a flange 59 projecting from the edge of the downwardly concave cover 60 of the auxiliary motor casing. The diaphragm 58 divides the auxiliary motor casing into upper and lower chambers-361 and 62 respectively, the latter communicating freely with the atmosphere by means of a port 63. l

A partition 64 ext-ending across the base member' 46 of the auxiliary motor casing forms the bottom of the chamber 62 and this partition 64 is furnished with a centrally disposed boss 65 having a guideway or passage for the reception of a sliding stem 66.

The central part of the diaphragm 58 of the auxiliary motor clamped between stiiicning plates 67 furnished with openings for the reception of the reduced, screw threaded upper end 68 of; the stem 66. A nut 69 holds the stem, the plates 67, and the diaphragm in assembled relation.

The cover member 60 of theI auxiliary motor casing is furnished with a centrally disposed upstanding boss 70 provided with a guide opening axially aligned with the stern 66. An abutment rod 71 slides freely in this Ouide opening. The unner end of the rod '71 is screw threaded for the reception of an adjustable stop nut which limits the movement of the rod 71 in its guideway.

4 wherein the port tu' is out oit regi try with the poi-t 9S although the auxiliary valve Q/O is still in engagement with its seat 8l.

So long as the parts remain in this position the chamber 29 of the main motor casing is cut off entirely from the transmission t-ube and exhauster so that the pressure slowly builds up by leakage through the orifice l2 until the spring 40 is able to depress the diaphragm 46, thus closing the main valve. As soon as the main valve closes, the pressure in the transmission tube increases very substantially and this increase in pressure being transmitted through the passage 94 to chamber 6l of the auxiliary motor casing builds up pressure in the latter until the diaphragm 5S drops and restores the valve 80 to its normal open position, when the parts are ready for a repetition of the foregoing series oit operations.

Vhile ordinarily the weight of the diaphragm 58 and the parts supported thereby is depended upon for returning it to its normal position, it is contemplated that a light spring 91 may be provided to assist in restoring it to normal position ii circumstances should indicate this to be necessary or desirable.

While one desirable arrangement of parts has been illustrated and described as exemplifying the invention, it is to be understood that the invention is not necessarily restricted to the exact arrangement herein disclosed but that various changes in proportions ot parts, as wel] as in the shapes and relative arrangement of the various elements constituting the mechanism, may be made Without departing from the spirit of the invention.

I claim:

l. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve for controlling the flow of air-,through the transmission tube, a minimum flow of air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating' the main valve, said motor responding to slight drop in pressure in the transmission tube incident to insertion of a carrier in the tube to open the main valve, and means :tor deterniining` subsequent pressure conditions in the main. motor comprising an auxiliary pneiniiatic responsive to pressure change in the transniission tube, and means actuable thereby itfor cutting oli' communication between the main lnotor and the transmission tube when the main valve opens and for innnediately rfi-establishing such communication, said auxiliary pneumatic subsequently responding to change iu pressure in the transmission tube incident to delivery of the carrier therefrom again to cut oi'f 'such communication.

2. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve for controllingl the flow of air through the transmission tube; a minimum flow ot' air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motorhaving a chamber and a pair ot' passages either of which is adapted to connect the chamber with the transmission tube, one at least of said passages normally being open, the motor responding to drop in pressure in the transmission tubel due to cutting oif ot minimum iow by introduction of a carrier to open the main valve, and means for de` termining subsequent pressure conditions in the motor chamber comprising a pair of auxiliary valves for controlling the respective passages, one of Said valves closing one ot said passages when the main valve opens1 the other passage being open during substantially the entire flight of the carrier, and the other valve also closing its passage when the last carrier emerges from the transmission tube thereby completely to shut off the motor chamber from the transmission tube.

3. Pneumatic despatch apparatus having a transmission tube and a main valve for controlling the flow of air through the transmission tube, and a pneumatic motor for opera-ting the main valve, said motor having a chamber and a pair ot passages either of which is adapted to connect the chamber with the transmission tube, one at least of said passages normally being open, the motor responding to change in pressure in the transmission tube to open the main valve, and means for determining subsequent pressure conditions in the motor chamber comprising an auxiliary pneumatic responsive to pressure change in the transmission tube, a pair of auxiliary valves actuable by the auxiliary pneumatic for controlling the respective passages, said pneumatic closingl one of said valves when the main valve opens and immediately thereafter' opening the other valve and holding it open during the flight of the carrier, said auxiliary pneumatic responding to the slight change in pressure in the transmission tube incident to delivery ot the last carrier therefroi'n to close said last named auxiliary valve,

4t. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve't'or controlling the tloiv otl air through the transmission tube, a minimum tlow ot air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a chamber normally connnunicating with the transmission tube by means of an open passage, an auxiliary valve for closing said passage, means -for closing the auxiliary valve when the main valve opens, and a cut-oit valve normally closing a second passage between the motor chamber and transmission tube, said cut-ofi' valve opening after the auxiliary valve closes. i

5. Pneumatic despatch apparatus having a transmission tube` means for producing carrier propelling air flew in the tube, a main valve for controlling the flow of air through the transmission tube, and a pneumatic motor for operating the main valve, said motor having` a chamber normally coniinunicating with the transmission tube by means of an open passage, an auxiliary valve tor closing said passage, cut-off valve noi'- mally closing a second passage leading from the motor chamber to the transmission tube, and means responsive to pressure change in the transmission tube due to' opening of the main valve Jfor closing the auxiliary valve and opening the .cut-ott" valve.

6. Pneumatic despatch apparatus having a ytransmission tube. an exhauster connected therewith and a main valve for controlling the Hoiv of air through the transmission tube, a minimum flow of air through the tube being permitted when tli-e valve is in closed position, and a pneumatic. motor for operating the main valve, said motor having a chamber normally communicating with the transmission tube by means of an open passage, an auxiliary valve for closing said passage, a cut-off valve normally closing a second passage leading from the motor chamber to the transmission tube, and an auxiliary pneumatic motor responsive to pressure change in the transmission tube, said auxiliary 4motor closing the auxiliary valve and opening the cut-off valve iiiimediatelyatter .the main valve opens and subsequently closing the cut-ofi' valve while. still keeping the auxiliary valve closed.

7. Pneumatic despatch api'iaratus havingl i a transmission tube, means tor creating carrier propelling air vtloiv therein, and a iiiaiii valve for controlling the tloiv ot air through the transmission tube, and a pneumatic inotor for operating the main valve, said motor having a chamber normally communicating With the transmission tube by means of an open passage, an auxiliary valve for closing said passage, an auxiliary pneumatic motor vhaving a flexible diaphragm, a stem secured to the diaphragm, said stem constituting a cut-off valve normally closing a second passage leading from the valve chamber to the transmission tube, and means connecting the auxiliary valve to said stem.

8. Pneumatic despatch apparatus having a transmission tube,an exhauster connected therewith and a main valve toi' controlling the flow ot air through the transmission tube, a minimum flow of air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a chamber normally communicating with the transmission tube by means of an open passage, an auxiliary valve for closing said passage, an auxiliary pneumatic responsive to pressure variation in the transmission tube, and means connecting the auxiliary valve to the auxiliary pneumatic, said connecting means being yieldable to permit relative movement of the pneumatic and valve. f

9. Pneumatic despatch apparatus having a. transmission tube, means tor creating carrier iinpelling air flow therein and a main valve for controlling the tloiv ot air through the transmission tube, and a pneumatic mbotor 'tor operating the main valve, said motor having a chamber normally cominuiiicatiim` With the transmission tube by means of aici open passage, an auxiliary valve `for closinO' said passage, a seat for said auxiliary valve3 an auxiliary pneumatic responsive to presj sure variation, and means connecting the auxiliary valve to the auxiliary pneumatic, said connecting means comprising a yieldal ble resilient part permitting the pneumatic to move independently of the valve ivliilc the latter engages the seat.

l0. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve for controlling the flow o t air through the transmissioii tube, a minimuni loW ot' air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said moto 1 havinv a chamber and a passage for transmitting' transmission tube pressure to said chamber, a normally closed valve controlling said passage, and an auxiliary pneumatic for openM ing` said valve during the flight ot a carrier through the transmission tube.

il. Pneumatic despatch apparatus having a transmission tube, means for creating can rier iinpellingl air flow therein, and a main valve -for controlling the flow of air through the transmission tube, and a pneumatic motor ior operating the main valve, said motor having a chamber and a passage for transmitting' transmission tube pressure to said chamber, a normally closed valve controlling said passages, and an auxiliary pneumatic responsive to pressure change in the transmission tube to hold said normally closed valve open during flight of a carrier through the transmission tube and to permit said valve to close When the last carrier emerges vfrom the tube.

Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a niain valve tor controlling the den' ot air through the transmission tube, a minimum flow of air through the tube be` ing permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a rhar-ile' normally communicating with the transmissii'm tube by means of an open passage. an auxiliary valve ior closing said pasi-agje, an auxiliary motor comprising a tiexible diaphragm havin,gl a stem, said stem iig through an opening in the auxiliary and spaced stop elements permitting lim-.ted relative n'iovement ot' the stem and valve.

i3. llneumatic despatch apparatus having a transn'iission tube, means tor creating carrier impelling air flow therein, and a main valve ttor controllii'ig the flow ot air through the tra is ion tube, and a pneumatic motor 'tor operating the main valve, said motor having a chamber normally eonnnunicating with the transmission tube by means of an open sage, an auxiliary valve 'torclosing said p. cage, an auxiliary motor comprising a tlexible diaphragm having a stem, one end oi" the stein sliding freely in a central opening in the auxilary valve, a stop element carried by the stem, and a coil spring encircling the stem and normally holding the valve against the stop element.

l-l. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve for controlling the flow o't' air through the transmission tube, a minimum flow of air through the tube being permitted when the'valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a chamber and two passages providing communication between the chamber and the transmission tube, and valve means for controlling said passages, said valve means closing one passage and opening the other upon opening ot the main valve responsive to insertion ol.t a carrier into the transmission tube and closing both passages when the last ear r emerges 'from the lube.

lo. Pneumatic despatch apparatus having a, transmission tube, means tor creating a carrier impelling air flow therein, and a u in valve tor controlling the flow of air through the transmission tube, and a pneumatic motor for operating the main valve, said motor having a chamber and a. pair of passages tor adn'iitting transmission tube l'ressure to said chamber, valves for controlling the respective passages, an ai'ixiliary pneumatic responsive to drop lin pressure in the transl sion tube 'for closing one ol said valves and responsive to continued low pressure in said tube to open the other valve, said pneumatic responding to subsequent slight increase in pressure in the tube to close the latter valve without opening the first valve.

16. Power control apparatus for a pneumatic despatch system comprising a pneumatic motor having a flexible diaphragm provided with a stem, a valve carried by the stem, a movable abutment normally spaced from but engageable by the stem, and resilient means tending to retain said abutment in normal position.

17. Power control apparatus for a pneumatic despatch system comprising a pneumatic motor having a flexible diaphragm provided with a stem, a slidable abutment spaced from but engageable by the stem as the diaphragm moves in one direction, a yoke secured to the abutment, and springs engaging the opposite ends of the yoke and tending to retain the abutment in normal position.

18. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve for controlling the flow of air through the transmission tube, a minimum flow of air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a chamber and two passages for admitting transmission tube pressure to the chamber, an auxiliary motor having a flexible diaphragm, a stem secured to the diaphragm, said stem constituting a valve for controlling one of said passages, and an auxiliary valve mounted upon the stem for controlling the other passage.

19. Pneumatic despatch apparatus having a. transmission tube, an exhauster connected therewith and a main valve for controlling the flow of air through the transmission tube, a minimum flow of air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a chamber and two passages for admitting transmission tube pressure to the chamber, an auxiliary motor having a` flexible diaphragm, a stem secured to the diaphragm, said stem having an axial passage and a port opening through its side and constituting a valve for controlling one of said passages, and a valve disk mounted upon the stem for controlling the other passage.

20. Pneumatic despatch apparatus having a transmission tube, an exhauster connected therewith and a main valve for controlling the flow of air through the transmission tube, a minimum flow of air through the tube being permitted when the valve is in closed position, and a pneumatic motor for operating the main valve, said motor having a chamber and two passages vtor admitting transmission tube pressure to the. chamber, an auxiliary pneumatic motor having a. chamber closed at one side by an auxiliary diaphragm, a stem secured to the diaphragm having an. axial passage opening into said chamber ol the auxiliary motor, the stem also having ports in its sides and constituting a Valve for controlling,l one of said passages, and a valve actuable by the stem for controlling the other passage.

2l. Pneumatic despatch apparatus having a transmission tube, and a main valve for controlling the flow oi' air through the transmission tube, and a pneumatic motor 4for operating the main valve, said motor having a chamber normally communicating with the 10 transmission tube by means of an open passage, an auxiliary Valve for closing,` said passage, means for closing the auxiliary valve when the main valve opens, and means op erative subsequently to the closure of the auxiliary valve for openingl communication through another1 passage between the motor chamber and the transmission tube.

Signed by me at Syracuse, New York, this 25th day of March 1925.

JAMES T. COlVLEY. 

